Exercise device

ABSTRACT

An exercise device ( 10 ) for working and stimulating the legs of disabled children is disclosed. The exercise device ( 10 ) includes a portable housing ( 12 ), a crankshaft ( 14 ) rotatably mounted in the housing ( 12 ), and a power source ( 16 ) coupled to the crankshaft ( 14 ). The power source ( 16 ) and the crankshaft ( 14 ) cooperate to provide the exercise device ( 10 ) an active operating mode, wherein rotation of the crankshaft ( 14 ) is resisted, and a passive operating mode, wherein rotation of the crankshaft ( 14 ) is assisted.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to equipment forexercising a user's lower limbs and related muscles. More specifically,the present invention concerns a portable, self-contained exercisedevice used for working and stimulating the legs of children.

[0003] 2. Discussion of Prior Art

[0004] Therapeutic exercise devices are frequently used by convalescingand disabled individuals to exercise otherwise insignificantly usedlimbs and related muscles and tissues to prevent them from atrophyingand to prevent the cartilage around the bones from hardening associatedwith limb disuse. Children who are subject to minor or severe physicaldisabilities that render them incapable of adequately exercising theirlimbs and related muscles and tissues through their own neuro-physicalcapabilities also suffer from the atrophying and hardening effects oflimb disuse.

[0005] Known prior art exercise devices include machines that resist anadult user's limb movement and machines that assist an adult user withlimb movement. Unfortunately these prior art exercise devices areproblematic and have several limitations for child users, particularlysmall children (e.g., children between the ages of 2-8 years). The priorart exercise devices are not adapted for use by children andconsequently are either unusable by children (e.g., children cannotreach the moving mechanism when seated in the device) or presentundesirable safety problems when misused by children (e.g., children aresubject to falling out/off the device, their knees are not angledsufficiently to avoid hyper-extension, etc.).

SUMMARY OF THE INVENTION

[0006] The present invention provides an improved exercise device thatdoes not suffer from the problems and limitations of prior art devicesas set forth above. The inventive exercise device portable andself-contained and is specifically adapted for safe use by smallchildren.

[0007] The exercise device of the present invention broadly includes aportable housing adapted to securely support a child therein, acrankshaft rotatably mounted in the housing and adapted to be rotated bythe legs of the child, and a power source associated with the housingand coupled to the crankshaft and operable to cooperate with thecrankshaft to provide an active operating mode, wherein rotation of thecrankshaft is resisted, and a passive operating mode, wherein rotationof the crankshaft is assisted.

[0008] Other aspects and advantages of the present invention will beapparent from the following detailed description of the preferredembodiment and the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0009] A preferred embodiment of the invention is described in detailbelow with reference to the attached drawing figures, wherein:

[0010]FIG. 1 is a perspective view of an exercise device constructed inaccordance with a preferred embodiment of the present invention;

[0011]FIG. 2 is a plan view of the exercise device with the guardsbroken away to show the power source;

[0012]FIG. 3 is a side elevational view of the exercise device with theport sidewall broken away and illustrating the seat assembly in both thestern-ward position (shown in solid) and the bow-ward position (shown inphantom); and

[0013]FIG. 4 is a fragmentary plan view of the exercise deviceillustrating the control unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014]FIG. 1 illustrates an exercise device 10 constructed in accordancewith a preferred embodiment of the present invention and configured forworking and stimulating the legs of disabled children. The exercisedevice 10 is portable and self-contained and is particularly adapted foruse by small children, for example, children between the ages of 2-8years with heights ranging between 32″-56″. The exercise device 10broadly includes a portable housing 12, a crankshaft 14 rotatablymounted in the housing 12, and a power source 16 coupled to thecrankshaft 14.

[0015] Turning initially to FIG. 1, the housing 12 provides portabilityand self-containment for the device 10 and is adapted to securelysupport a child therein. The housing 12 includes a base 18, a pair ofsidewalls 20,22, a front wall 24, a rear wall 26 and a seat assembly 28.The base 18 is flat, generally rectangular shaped, and sufficientlyconstructed and dimensioned to support the walls 20, 22, 24, 26, thecrankshaft 14 and power source 16 with their associated components, anda child user. Mounted on the bottom surface of the base 18 are fourswivel casters 30, each one rollably mounted on the base 18 at arespective corner thereof. The casters 30 facilitate the portability ofthe exercise device 10 (e.g., rolling the device 10 across a groundsurface) and are operable to selectively prevent rolling movementthereof. Particularly, in a manner known in the art, each caster 30includes a breaking mechanism 30 a that is shiftable between a lockingconfiguration (wherein rolling of the caster relative to the groundsurface is prevented) and a free-wheeling configuration (wherein thecaster is free to roll across the ground surface). The casters 30 arepositioned at the corners of the base 18 so that a portion of thebreaking mechanisms 30 a sufficiently protrude out from under the base18 to allow them to be manually shifted into and out of the lockingconfiguration.

[0016] The sidewalls 20,22 are flat and generally parallel to oneanother extending upward from the top surface of the base 18. The frontand rear walls 24,26 are disposed between the sidewalls 20,22 andpositioned at the front and rear thereof, respectively. The walls 20,22, 24, 26 cooperate to define a compartment sufficient to house thecrankshaft 14, the power source 16, and the seat assembly 28. Thecompartment has a bow section adjacent the front wall 24 and a sternsection adjacent the rear wall 26. The sidewalls 20,22 must besufficiently spaced from one another to provide adequate clearance for achild to sit between them (e.g., a child between the ages of 2-8 years).A representative sidewall width dimension (designated as D_(W) in FIG.2) is approximately between 8″-16″, and most preferably approximately12″. The sidewalls 20,22 have a profile shape resembling the profileshape of an automobile to aesthetically enhance use of the device 10 bychildren.

[0017] The seat assembly 28 is slidably mounted in the housing 12 at thestern section thereof. The seat assembly 28 is adapted to support achild in an upright orientation and includes a seat member 28 a, a backmember 28 b, and a pair of side members 28 c that gusset the seat member28 a to the back member 28 b. As will subsequently be discussed indetail, the crankshaft 14 is mounted in the housing 12 at the bowsection thereof. The seat assembly 28 is adjustable relative to thecrankshaft 14. Particularly, the seat assembly 28 is slidable between astern-ward position as shown in solid lines in FIG. 3, wherein the seatassembly 28 is adjacent the rear wall 26, and a bow-ward position asshown in phantom lines in FIG. 3, wherein the seat assembly 28 isadjacent the crankshaft 14. The seat member 28 a is supported by, andslides in, a pair of complemental grooves, one each formed in arespective sidewall 20,22. To facilitate supporting the weight of theseat assembly 28 (and a child user therein), the illustrated housing 12includes an additional support member (not shown) disposed between thesidewalls 20,22 positioned generally below the seat assembly 28 andconfigured to provide unobstructed sliding of the seat assembly 28. Theseat assembly 28 includes a locking mechanism that cooperates with thesidewall 20 to lock the seat assembly 28 in the stern-ward and bow-wardpositions, as well as positions intermediate thereto. Particularly, thelocking mechanism comprises a detent assembly 32 (having a pin) securedto the sidewall 20 by a wire 34 and mounted in an aperture in thesidewall 20. The seat member 28 a includes apertures formed in the portside thereof that correspond to the stern-ward, bow-ward, andintermediate positions and configured to receive the pin of the detentassembly 32.

[0018] The seat assembly 28 further includes a seat belt 36, a chestbelt 38 and a handgrip assembly 40. The seat and chest belts 36,38 areeach adjustable (e.g., utilizing a velcro-type clasp, a slip buckle,etc.) operable to securely retain various sized children in the seatassembly 28. The seat belt 36 is coupled to the back member 28 badjacent the seat member 28 a. The chest belt 38 is coupled to the sidemembers 28 c spaced from the seat belt 36 and cooperates with the backmember 28 b to retain a child user in an upright position while usingthe exercise device 10. The handgrip assembly 40 is mounted on the seatmember 28 a adjacent the front edge thereof and includes a collar 42gusseted to the bottom surface of the seat member 28 a, a column 44removably and slidably received through the seat member 28 a and intothe collar 42, and a wheel 46 rotatably coupled to the column 44. Thewheel 46 can be gripped and rotated by the child user to facilitateupper body stimulation of the child user. The handgrip assembly 40 isadjustable to accommodate child users of varying sizes and is alsoremovable so that the exercise device 10 can be used without thehandgrip assembly 40. Particularly, the column 44 includes a detentbutton configured to cooperate with apertures in the collar 42 so thatthe column 44 can slide between various height adjusted positions or canbe entirely removed from the collar 42. The wheel 46 is rotatablerelative to the column 44 and is designed to resemble a steering wheelof an automobile to aesthetically enhance use of the device 10 bychildren. The wheel 46 includes a shaft 46 a that is slidably androtatably received into a flange 44 a formed in the upper end of thecolumn 44 so that the wheel 46 may be adjusted relative to the childuser seated in the seat assembly 28.

[0019] The housing could utilize various alternative designs,configurations, and materials; however, it is important that the housingbe adapted to securely and safely support a child user therein. It iswithin the ambit of the present invention to utilize alternative designsthat are pleasing to children, for example, the housing could resembleobjects other than an automobile, be brightly colored, etc. The housingcould utilize a myriad of alternative configurations so long as thehousing is adapted to be used by children. The support structure of thehousing (e.g., the base, the walls, etc.) can be formed of any suitablematerial of sufficient strength to support the necessary components andthe child user such as wood, molded plastic, metal, etc.

[0020] The crankshaft 14 includes a pair of spaced apart cranks 14 a, 14b adapted to be rotated by the legs of a child user and is rotatablymounted in the housing 12 generally at the bow end section thereof (seeFIGS. 2 and 3). Particularly, the crankshaft 14 is supported on bushingsin each of the sidewalls 20,22 and sufficiently spaced from the base 18to provide adequate clearance so that the crankshaft 14 can rotateunobstructed by the housing 12. For purposes that will subsequently bedescribed, the port end of the crankshaft 14 extends through thesidewall 20 so that a portion thereof protrudes out of the sidewall 20(see FIG. 2). A pair of shoe plates 48,50 are rotatably coupled to thecorresponding cranks 14 a, 14 b. The shoe plates 48,50 have a boot-likeconfiguration with a padded inside surface that facilitates the comfortof the child user. Each of the shoe plates 48,50 has a correspondingpair of straps 48 a, 48 b and 50 a, 50 b coupled thereto. The straps 48a, 48 b, 50 a, 50 b are each adjustable (e.g., utilizing a velcro-typeclasp, a slip buckle, etc.) and operable to securely retain varioussized children's feet in the shoe plates 48,50.

[0021] The crankshaft 14 is operable to be rotated in either a clockwiseor counterclockwise direction (when viewed from the port side asillustrated in FIG. 3). The crankshaft 14 is sufficiently spaced fromthe seat assembly 28 to enable a child user seated in the seat assembly28 to comfortably reach the shoe plates 48,50 with their feet. Aspreviously detailed, the seat assembly 28 is slidably adjustablerelative to the crankshaft 14 to accommodate various sized children.Representative length dimensions from the axial center of the crankshaft14 to the front edge of the seat member 28 a (designated as DL1 and DL2in FIG. 3) are between 12″-16″, and most preferably 14″ for DL1 whereDL1 corresponds to the seat assembly 28 being in the stern-ward positionand between 7″-11″, and most preferably 9″ for DL2 where DL2 correspondsto the seat assembly 28 being in the bow-ward position.

[0022] The crankshaft could utilize various alternative designs,configurations, and materials; however, it is important that thecrankshaft be adapted to be rotated by the legs of a child user. Thecrankshaft could utilize a myriad of alternative configurations so longas the crankshaft is adapted to be used by children, for example, thecrankshaft could be elevated above or below the seat assembly andutilize an alternative crank arrangement. The crankshaft can be formedof any suitable material of sufficient strength to endure the wear andtear of repeated use by children such as steel, iron, metal alloys,wood, molded plastic, etc.

[0023] The power source 16 is in power communication with the crankshaft14 and includes a motor 52 and a micro-controller 54 (see FIG. 2). Themotor 52 is mounted on the inside surface of the sidewall 20 generallyat the bow end thereof adjacent the crankshaft 14. The motor 52 drivesone end of an output shaft 56. The output shaft 56 extends through thesidewall 20 and has a drive sprocket 58 fixed on the opposing endadjacent the outside surface of the sidewall 20. A chain 60 entrains thedrive sprocket 58 and extends therefrom to entrain a driven sprocket 62.The driven sprocket 62 is fixed to the end of the crankshaft 14 thatprotrudes through the sidewall 20. The sprockets 58,62 and the chain 60are housed within a chain guard 64 attached to the outside surface ofthe sidewall 20. The micro-controller 54 is in wire communication withthe motor 52 and is attached to the inside surface of the front wall 24.The motor 52 and the micro-controller 54 are housed within a motor guard66 attached to the front wall 24 and the base 18.

[0024] The illustrated motor 52 is a reversible, variable speed electricgearmotor. One suitable motor is available from Groschopp, 420 15thStreet N.E., Souix Center, Iowa 51250-2100 as model SM60151960 withreducer model PS 1900, rated at 1600 rpm with a ratio of 60:1. However,it is within the ambit of the present invention to utilize any suitabledrive source, for example, a motor and a separate gear box.

[0025] The motor 52 and the crankshaft 14 cooperate to provide theexercise device 10 an active operating mode, wherein rotation of thecrankshaft 14 is resisted, and a passive operating mode, whereinrotation of the crankshaft 14 is assisted. In the active operating mode,the exercise device 10 is used as a simple reciprocating device whereinthe child user rotates the crankshaft 14 using their legs in order tostrengthen the related muscles and tissues. In the passive operatingmode, the motor 52 rotates the crankshaft 14 so that the child user isinduced to move their legs in response to the rotation of the crankshaft14 in order to improve circulation of body fluids, increase bonedensity, etc.

[0026] When the exercise device 10 is in the active operating mode, themotor 52 exerts a resistance force on the crankshaft 14 that resistsrotation thereof (e.g., if the user is rotating the crankshaft 14 in aclockwise direction, the resistance force is acting against thecrankshaft 14 in a counterclockwise direction). When the exercise device10 is in the passive operating mode, the motor 52 exerts an assistanceforce on the crankshaft 14 that assists rotation thereof (e.g., theassistance force is acting in the same direction that the crankshaft 14is rotating—clockwise or counterclockwise). Each of the resistance andassistance forces include a quantity, a speed, a direction, and aduration component. The quantity component concerns a percentage rangingfrom 0-100% of the maximum force exertable by the motor 52. The speedcomponent concerns the rate at which the output shaft 56 rotatesmeasured in revolutions per minute. The direction component concerns thedirection the output shaft 58 rotates—either clockwise orcounterclockwise (when viewed from the port side of the device 10 asillustrated in FIG. 3). The duration component concerns the time themotor 52 operates measured in minutes.

[0027] Each of the force components—quantity, speed, direction, andduration components—are selectively variable by the user. Particularly,the micro-controller 54 communicates with the motor 52 and is operableto receive an input setting relating to one or more of the forcecomponents, convert the input setting into a motor-controlling signal,and output the signal to the motor 52.

[0028] Some children, particularly disabled children, suffer spasticepisodes where the nerves affecting their legs jolt and the relatedmuscles and tissues in the legs lock up. It is therefore preferable forthe exercise device to have the ability to detect when a child usersuffers a spastic episode and initiate safety precautions in response tosuch a detection (e.g., shut off the motor, stop rotation of thecrankshaft, etc.). In the illustrated device 10, the power source 16 isoperable to sense an interrupt force, wherein the interrupt force is aforce acting in a direction opposite of the direction of the resistanceforce when the exercise device 10 is in the active operating mode andopposite the assistance force when the exercise device 10 is in thepassive operating mode. The power source 16 compares the interrupt forcesensed thereby with a threshold force, wherein the threshold force is apreset selectable value sufficient to ensure that the device 10 isadequately detecting a spastic episode by the child user. When theinterrupt force exceeds the threshold force, the motor 52 will notrotate the crankshaft 14. In the illustrated exercise device 10, thethreshold force corresponds with the quantity component of the motor 52and is therefore selected by the user/operator. The appropriatethreshold force will vary from user to user and therefore is preferablyinitially set each time by the user/operator and adjusted as necessaryafter the user begins using the device 10. A representative range ofexemplary threshold forces is 10-50%. The micro-controller 54 couldalternatively include an interrupt switch operable to switch powercommunication between the motor 52 and the crankshaft 14 into and out ofan activated position, wherein power is supplied from the motor 52 tothe crankshaft 14. In this alternative configuration, themicro-controller 54 could output a control signal that causes theinterrupt switch to switch the power communication out of the activatedposition when the interrupt force exceeds the threshold force.

[0029] Some children users may have stiffness in their legs when theyinitially begin using the exercise device, particularly disabledchildren; however, this stiffness typically subsides after some warm-upuse of the device. It is therefore preferable for the exercise device tohave the ability to “soft start” wherein the power source graduallycomes up to speed. In the illustrated device 10, the motor 52 of thepower source 16 rotates multiple revolutions (e.g., at least two) beforeachieving the selected speed. Additionally, the quantity componentoutput by the motor 52 is selectively variable by the user; therefore,the component can be increased or decreased (depending on the mode ofoperation) as the stiffness in the user's legs subsides. As previouslydiscussed, in the illustrated exercise device 10, the quantity componentcorresponds to the threshold force, therefore, it is important to adjustthe quantity component once stiffness in the user's legs subsides inorder to optimize the anti-spasm safety feature of the device 10. Forexample, if the exercise device 10 is in the passive operating mode andstiffness in the user's legs requires an initial quantity componentsetting of 40% but once the stiffness subsides, only a 30% quantitycomponent is needed, the operator should adjust the quantity componentdown to 30% to ensure the motor 52 does not rotate the crankshaft 14 ifthe user experiences a spasm that generates an interrupt force ofgreater than 30% but less than 40%.

[0030] As previously discussed in detail, the user can selectively varymany of the functions of the power source 16, for example, the forcecomponents outputted by the motor 52. Particularly, the illustratedexercise device 10 includes a remote control unit 68 and an externalOn/Off switch (not shown). The control unit 68 communicates with themicro-controller 54 by a cable 70 that enables the unit 68 to beoperated by an individual external to the housing 12 (e.g., a healthcare provider located in the same room as the child user and the device10). The control unit 68 includes multiple input keys 68 a, operable forthe user to input data corresponding to starting/stopping the powersource 16 and selecting/varying the force components output by the motor52, a display screen 68 b cooperating with the keys 68 a and operablefor the user to view information relating to the input data, andindicator lights 68 c that indicate the specific component selected. Theillustrated control unit 68 includes input keys 68 a associated with:EMERGENCY STOP—highly visible (e.g., brightly colored and set-off fromthe other keys) and operable to stop the motor 52; MODE—operable totoggle between and select the relevant force component to be varied;PLUS—operable to vary the force component selected by the MODE key;MINUS—operable to vary the force component selected by the MODE key;START—operable to initiate operation of the power source 16 with theselected force component settings; and STOP—operable to terminateoperation of the power source 16. The illustrated control unit 68includes indicator lights 68 c associated with R.P.M. (speed), Minutes(duration), % Force (quantity), Direction, and Start/Run.

[0031] The EMERGENCY STOP input key 68 a of the illustrated control unit68 is in communication with an audible alarm (not shown). The audiblealarm sounds when the EMERGENCY STOP switch 68 a is activated. In thismanner, someone other than the child user (e.g., a health care providerlocated in the vicinity) is alerted that the child user has activatedthe EMERGENCY STOP.

[0032] The power source could utilize various alternative components toprovide and regulate power to the crankshaft, such as variouslyconfigured motors, micro-controllers, micro-processors, etc. However, itis important that the power source selectively provide both resistanceand assistance forces to the crankshaft that are safe for child users.

[0033] The preferred forms of the invention described above are to beused as illustration only, and should not be utilized in a limitingsense in interpreting the scope of the present invention. Obviousmodifications to the exemplary embodiments, as hereinabove set forth,could be readily made by those skilled in the art without departing fromthe spirit of the present invention.

[0034] The inventors hereby state their intent to rely on the Doctrineof Equivalents to determine and assess the reasonably fair scope of thepresent invention as pertains to any apparatus not materially departingfrom but outside the literal scope of the invention as set forth in thefollowing claims.

What is claimed is:
 1. An exercise device for working and stimulating the legs of a child, the device comprising: a portable housing adapted to securely support the child therein; a crankshaft rotatably mounted in the housing and adapted to be rotated by the legs of the child; and a power source associated with the housing and coupled to the crankshaft and operable to cooperate with the crankshaft to provide an active operating mode, wherein rotation of the crankshaft is resisted, and a passive operating mode, wherein rotation of the crankshaft is assisted.
 2. The exercise device as claimed in claim 1, said housing including a stern end and a bow end, said crankshaft being rotatably mounted generally toward the bow end of the housing, said housing further including a seat slidably mounted generally toward the stern end of the housing, said seat being slidable between a stern-ward position, wherein the seat is adjacent the stern end of the housing, and a bow-ward position, wherein the seat is adjacent the crankshaft.
 3. The exercise device as claimed in claim 2, said housing including a locking mechanism associated with the seat and being operable to lock the seat in the stern-ward position, the bow-ward position, and at least one position intermediate thereto.
 4. The exercise device as claimed in claim 2, said seat including at least one adjustable belt being operable to secure the child in the seat.
 5. The exercise device as claimed in claim 2, said seat including an adjustable handgrip removably and rotatably coupled to the seat.
 6. The exercise device as claimed in claim 5, said adjustable hand grip including a column removably coupled to the seat, and a wheel slidably and rotatably coupled to the column.
 7. The exercise device as claimed in claim 1, said crankshaft including at least one shoe plate rotatably coupled to the crankshaft.
 8. The exercise device as claimed in claim 7, said at least one shoe plate including an adjustable strap being operable to secure a foot of the child in the shoe plate.
 9. The exercise device as claimed in claim 1, said power source exerting a resistance force on the crankshaft operable to resist rotation thereof when in the active operating mode, said power source exerting an assistance force on the crankshaft operable to assist rotation thereof when in the passive operating mode, said resistance and assistance forces each including quantity, speed, direction, and duration components.
 10. The exercise device as claimed in claim 9, said resistance and assistance forces exerted by the power source each being selectively variable with respect to the quantity, speed, direction, and duration components.
 11. The exercise device as claimed in claim 9, said power source including a micro-controller operable to sense an interrupt force, wherein the interrupt force is a force acting in a direction opposite of the direction of the resistance force when the power source is in the active operating mode and opposite the assistance force when the power source is in the passive operating mode, said micro-controller further operable to compare the interrupt force sensed thereby with a threshold force, wherein the threshold force is a preset selectable value.
 12. The exercise device as claimed in claim 11, said power source further including an interrupt switch operable to switch power communication between the power source and the crankshaft into and out of an activated position, wherein power is supplied from the power source to the crankshaft, said micro-controller being in communication with the interrupt switch and being further operable to output a control signal that causes the interrupt switch to switch said power communication out of the activated position when the interrupt force exceeds the threshold force.
 13. The exercise device as claimed in claim 12, said power source including a shut off switch operable to switch said power communication into and out of the activated position.
 14. The exercise device as claimed in claim 10 further comprising: a remote controller associated with the power source and operable to remotely select variations of the quantity, speed, direction, and duration components.
 15. The exercise device as claimed in claim 14, said remote controller being further operable to switch power communication between the power source and the crankshaft into and out of an activated position, wherein power is supplied from the power source to the crankshaft.
 16. The exercise device as claimed in claim 15 further comprising: an alarm in communication with the remote controller and being operable to activate when the remote controller switches power communication between the power source and the crank shaft out of the activated position.
 17. The exercise device as claimed in claim 10, said power source being an electric motor.
 18. An exercise device comprising: a housing; a crankshaft rotatably mounted in the housing; and a power source contained in the housing and being in power communication with the crankshaft, said power source cooperating with the crankshaft to provide a passive operating mode, wherein the power source exerts an assistance force on the crankshaft operable to assist rotation thereof, said power source being further operable to sense an interrupt force, wherein the interrupt force is a force acting in a direction opposite the assistance force, and terminate rotation of the crankshaft when the interrupt force exceeds the assistance force.
 19. The exercise device as claimed in claim 18, said assistance force being selectively variable.
 20. The exercise device as claimed in claim 19, said power source including a micro-controller operable to sense the interrupt force and compare the interrupt force sensed thereby with a threshold force, wherein the threshold force is a preset selectable value.
 21. The exercise device as claimed in claim 20, said power source further including an interrupt switch operable to switch power communication between the power source and the crankshaft into and out of an activated position, wherein the assistance force is supplied from the power source to the crankshaft, said micro-controller being in communication with the interrupt switch and being further operable to output a control signal that causes the interrupt switch to switch said power communication out of the activated position when the interrupt force exceeds the threshold force.
 22. The exercise device as claimed in claim 21, said power source further including a soft-start function, wherein said power source gradually increases the assistance force when power communication is switched into the activated position until the selected assistance force is achieved. 